A model for condensate retention on plain-fin heat exchangers

作者:ElSherbini AI*; Jacobi AM
来源:Journal of Heat Transfer-Transactions of the ASME, 2006, 128(5): 427-433.
DOI:10.1115/1.2175091

摘要

A model has been developed for predicting the amount of condensate retained as drops on the air-side of heat exchangers operating under dehumidifying conditions. For a coil with a given surface wettability characterized by the advancing contact angle, the maximum diameter for a retained drop is obtained from a balance between gravitational and surface tension forces. A logarithmic function is used to describe the size-distribution of drops on fins, based on the fraction of fin-area covered by liquid. The volumes of individual drops are calculated by a geometric method for approximating the three-dimensional shapes of drops on vertical and inclined surfaces. The total volume of condensate accumulated on a coil is then found by multiplying the size-distribution and volume functions and integrating over all drop diameters. The model is successful in predicting measurements by other researchers of the mass of condensate retained on plain-fin heat exchangers. The critical fin spacing to avoid the formation of condensate bridges is also predicted.

  • 出版日期2006-5